Environmentally-friendly technology for vehicles is a very important technology on which survival of future motor industry is dependent. Vehicle manufacturers are focusing on development of environmentally-friendly vehicles so as to meet environment and fuel consumption regulations.
Some examples of future vehicle technologies are an electric vehicle (EV) and a hybrid electric vehicle (HEV) using electrical energy and double clutch transmission (DCT) to improve efficiency and convenience.
The DCT includes two clutches and a gear train applied to a manual transmission. The DCT selectively transmits torque input from an engine to two input shafts by using the two clutches, changes a speed by using the gear train, and outputs the torque.
The DCT is one type of automated manual transmissions (AMT). It realizes a compact transmission having more than five forward speeds. Since the two clutches and synchronizers are controlled by a controller according to the DCT, manual shift maneuver is unnecessary for controlling the DCT.
The DCT, compared with an automatic transmission using planetary gear sets, has excellent power delivery efficiency, and implementation of additional components is simple. Therefore, the DCT can meet fuel consumption regulations, and multi-speeds efficiency may be improved.
However, the vehicle having the conventional DCT may not achieve smooth starting and may roll back when the vehicle starts on an uphill due to slipping of a friction clutch. Heat capacity of the clutch according to the conventional DCT may cause shift shock since shift time needs to be shortened.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.